scholarly journals Three-dimensional Ultrathin Planar Lenses by Acoustic Metamaterials

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Yong Li ◽  
Gaokun Yu ◽  
Bin Liang ◽  
Xinye Zou ◽  
Guangyun Li ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Acoustic Metamaterials

Engineering three-dimensional labyrinthine fractal acoustic metamaterials with low-frequency multi-band sound suppression

2021 ◽  
Vol 149 (1) ◽  
pp. 308-319
Author(s):  
Xianfeng Man ◽  
Baizhan Xia ◽  
Zhen Luo ◽  
Jian Liu ◽  
Kun Li ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Low Frequency ◽  
Acoustic Metamaterials ◽  
Sound Suppression ◽  
Multi Band

Acoustical Scattering by Multilayer Spherical Objects Containing Electrorheological Fluid

2009 ◽  
Author(s):  
Liang-Wu Cai ◽  
Dacio K. Dacol ◽  
Gregory J. Orris ◽  
David C. Calvo ◽  
Michael Nicholas
Keyword(s):  
Acoustic Wave ◽  
Fundamental Problem ◽  
Fluid Layer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Electrorheological Fluid ◽  
Acoustic Metamaterials ◽  
Spherical Object ◽  
Spherical Scatterer ◽  
Acoustic Media

Scattering is the most fundamental problem in the research on phononic crystals and acoustic metamaterials; and scattering in a three-dimensional space poses challenging issues; and yet, the most challenging of all, is the scattering by elastic objects since an acoustic wave splits into different types of waves, propagating at different speeds, when it enters an elastic object. In this paper, a unified formalism is developed to analyze the scattering of an acoustic wave by a multilayer spherical object that is made of a mixture of an arbitrary number of concentric layers of elastic and acoustic media. Using this formalism, acoustical scattering by a multilayer spherical scatterer encasing an electrorheological (ER) fluid layer in an underwater environment is studied. Numerical examples show that ER fluids can alter the scattering characteristics above the first resonant frequency, which itself can be tuned by the applied electric field.

Design and characterization of tunable three-dimensional acoustic composite metamaterials

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guochang Lin ◽  
Chaonan Hu ◽  
Lin Cong ◽  
Yongtao Yao
Keyword(s):  
Elastic Modulus ◽  
Structural Material ◽  
Cell Structure ◽  
Three Dimensional ◽  
Sound Insulation ◽  
Acoustic Metamaterials ◽  
Content Type ◽  
Acoustic Metamaterial ◽  
Material Parameters ◽  
Initial Frequency

Purpose The purpose of this paper is to developing a kind of acoustic metamaterial with wide frequency band especially in low frequency region. At the same time, its the tunability of sound insulation frequency is achieved. Design/methodology/approach A three-dimensional (3D) acoustic metamaterial consisting of rigid frame, spherical attachment and thin film is proposed. The material parameters and the effect of the attachment hole on the forbidden band are investigated by finite element simulation. The sound insulation effect of the structure is validated by the combination of simulation and experiment. Findings The results show that the elastic modulus of the structural material determines the initial frequency of the forbidden band of the proposed 3D acoustic metamaterials. The lower the elastic modulus of the structural material, the lower the initial frequency of the forbidden band. The material parameters of the frame mainly affect the initial frequency of the first forbidden band, and the material parameters of the attachment will affect both the initial and termination frequency of the first forbidden band. Holes in the attachments reduce the band gap width. The characteristic curve moves down with the increase of subtracted mass. Research limitations/implications The findings may greatly benefit the application of the acoustic metamaterials in the fields of sound insulation and noise reduction. Originality/value This acoustic metamaterial structure has excellent sound insulation performance. At the same time, the single cell structure can be assembled into any shape. The structure can achieve sound selective filtering and combination control.

scholarly journals Wavefront manipulation by acoustic metasurfaces: from physics and applications

Nanophotonics ◽  
2018 ◽  
Vol 7 (6) ◽  
pp. 1191-1205 ◽  
Author(s):  
Bin Liang ◽  
Jian-chun Cheng ◽  
Cheng-Wei Qiu
Keyword(s):  
Acoustic Waves ◽  
Review Paper ◽  
Three Dimensional ◽  
New Physics ◽  
Research Field ◽  
Acoustic Metamaterials ◽  
Future Directions ◽  
Practical Applications ◽  
The Past ◽  
Recent Developments

AbstractMolding the wavefront of acoustic waves into the desired shape is of paramount significance in acoustics, which however are usually constrained by the acoustical response of naturally available materials. The emergence of acoustic metamaterials built by assembling artificial subwavelength elements provides distinct response to acoustic waves unattainable in nature. More recently, acoustic metasurfaces, a class of metamaterials with a reduced dimensionality, empower new physics and lead to extended functionalities different from their three-dimensional counterparts, enabling controlling, transmitted or reflected acoustic waves in ways that were not possible before. In this review paper, we present a comprehensive view of this rapidly growing research field by introducing the basic concepts of acoustic metasurfaces and the recent developments that have occurred over the past few years. We review the interesting properties of acoustic metasurfaces and their important functionalities of wavefront manipulation, followed by an outlook for promising future directions and potential practical applications.

Acoustic Metamaterial Design Method Based on Green Coordinate Transformation

2020 ◽  
Vol 976 ◽  
pp. 15-24
Author(s):  
Xin Xie ◽  
Xiao Ming Wang ◽  
Yu Lin Mei
Keyword(s):  
Coordinate Transformation ◽  
Design Method ◽  
Three Dimensional ◽  
Transformation Method ◽  
Propagation Path ◽  
Acoustic Metamaterials ◽  
Acoustic Wave Propagation ◽  
Acoustic Metamaterial ◽  
Coordinate Transformation Method ◽  
Transformation Acoustics

Acoustic metamaterials have great application prospects in eliminating vibration and noise, but they are difficult to manufacture due to their anisotropy. This paper utilizes the Green coordinate transformation method to design acoustic metamaterials by combining with the transformation acoustics theory. Because the Green coordinate transformation is the pseudo-conformal mapping in three-dimensional coordinates, the anisotropy of designed metamaterials can be weakened. And also, the genetic algorithm is employed to optimize the anisotropy of metamaterials and reduce the designed metamaterial parameter difference further. Finally, the membrane-imbedded-type metamaterial is applied to realize the design and to illustrate the effectiveness of the proposed method by manipulating the acoustic wave propagation path.

Three-dimensional labyrinthine acoustic metamaterials

2013 ◽  
Vol 103 (6) ◽  
pp. 061907 ◽  
Author(s):  
Tobias Frenzel ◽  
Jan David Brehm ◽  
Tiemo Bückmann ◽  
Robert Schittny ◽  
Muamer Kadic ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Acoustic Metamaterials

scholarly journals Plane and Surface Acoustic Waves Manipulation by Three-Dimensional Composite Phononic Pillars with 3D Bandgap and Defect Analysis

Acoustics ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 25-41
Author(s):  
Muhammad ◽  
C.W. Lim ◽  
Andrew Y. T. Leung
Keyword(s):  
Acoustic Waves ◽  
Wave Attenuation ◽  
Numerical Technique ◽  
Surface Acoustic Waves ◽  
Three Dimensional ◽  
Phononic Crystals ◽  
Defect State ◽  
Two Dimensional ◽  
Defect Analysis ◽  
Acoustic Metamaterials

The current century witnessed an overwhelming research interest in phononic crystals (PnCs) and acoustic metamaterials (AMs) research owing to their fantastic properties in manipulating acoustic and elastic waves that are inconceivable from naturally occurring materials. Extensive research literature about the dynamical and mechanical properties of acoustic metamaterials currently exists, and this maturing research field is now finding possible industrial and infrastructural applications. The present study proposes a novel 3D composite multilayered phononic pillars capable of inducing two-dimensional and three-dimensional complete bandgaps (BGs). A phononic structure that consisted of silicon and tungsten layers was subjected to both plane and surface acoustic waves in three-dimensional and two-dimensional periodic systems, respectively. By frequency response study, the wave attenuation, trapping/localization, transmission, and defect analysis was carried out for both plane and surface acoustic waves. In the bandgap, the localized defect state was studied for both plane and surface acoustic waves separately. At the defect state, the localization of both plane and surface acoustic waves was observed. By varying the defect size, the localized frequency can be made tailorable. The study is based on a numerical technique, and it is validated by comparison with a reported theoretical work. The findings may provide a new perspective and insight for the designs and applications of three-dimensional phononic crystals for surface acoustic wave and plane wave manipulation, particularly for energy harvesting, sensing, focusing and waves isolation/attenuation purposes.

Focusing Properties of Axisymmetric Acoustic Metamaterials Made of Toroidal Scatterers

2012 ◽  
Author(s):  
V. Romero-García ◽  
R. Picó ◽  
A. Cebrecos ◽  
L. M. Garcia-Raffi ◽  
J. V. Sánchez-Pérez ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Axial Rotation ◽  
Acoustic Metamaterials ◽  
Effective Parameters ◽  
Radiation Properties ◽  
Homogenization Approach ◽  
2D System ◽  
Sonic Crystal ◽  
Axisymmetric Structure ◽  
Axisymmetric Structures

We present the theoretical analysis of a periodic structure based on a transformational design of an axisymmetric system from a two-dimensional (2D) Sonic Crystal (SC). Applying an axial rotation of a 2D SC, we obtain a three dimensional (3D) axisymmetric structure made up of toroidal scatterers. Based on the propagating properties of the 2D system, we interpret the scattering produced by the 3D axisymmetric structure, and one can also use the homogenization approach in the long wavelength regime to design a refractive media with controlled effective parameters. We use both the multiple scattering theory, for the analysis of the 2D systems, and the finite elements methods, for the case of 3D axisymmetric structures. This system, due to the axial symmetry, could be useful to manage the radiation properties of sources presenting that symmetry. Moreover it may be useful by transforming in scale to different sizes, and as a consequence, to be applied at different ranges of frequencies.

Sign in / Sign up

Export Citation Format

Share Document